This invention relates to steam generators for a pressurized water reactor and more particularly to a system and method for retubing the steam generator while the steam generator is disposed vertically in a containment vessel.
Pressurized water nuclear reactors utilize steam generators to transfer heat from a primary reactor coolant to a secondary fluid, which is vaporized forming steam that drives a steam turbine. Condenser leaks have caused circulating water, which is often brackish, to mix with the secondary fluid and enter the steam generator, resulting in the buildup of undesirable chemicals in the steam generator. Water treatment and blowdown have not completely protected the steam generator from corrosion, resulting in leaking tubes. As the number of leaking tubes increases the desirability of replacing a steam generator increases; however, the steam generators are located in a reinforced concrete vessel, a containment vessel, and removal of the steam generator requires tearing out a large portion of the reinforced concrete walls of the containment vessel. This is time consuming and expensive, therefore it is desirable to retube the steam generator in place within the containment vessel.